Investigations into the molecular targets of drugs of abuse and their associated intracellular signaling pathways have yielded a wealth of information regarding the cellular perturbations associated with these drugs. The combined studies outlined in Projects I-IV will extend upon this existing knowledge with rigorous cell biological, molecular, biochemical, behavioral, and electrophysiological studies of neuronal cells upon drug treatment. These studies have the potential to provide greater insights into the causes of drug dependence as well as to elucidate possible novel targets for pharmacological intervention. The Scientific Core will be a center devoted to facilitating those experiments proposed in Projects I-IV that require the use of genetically modified animals, yeast two-hybrid screens, and various key biological reagents. The experiments outlined in these Projects require the creation and maintenance of large numbers of genetically modified animals. The creation and characterization of necessary transgenic mice, and the maintenance of these and all other genetically modified mice is Specific Aim I of the Core. To help identify and characterize novel protein-protein interactions relevant to signaling molecules targeted by drug of abuse, the Core will design and execute yeast two-hybrid screens in Specific Aim II. In addition, the Scientific Core will be a key source of various reagents needed for the experiments outlined in Projects I-IV. Key proteins, enzymes, and antibodies will be produced in Specific Aim III,while new polyclonal antibodies, including phosphorylation state- specific antibodies, will be produced in Specific Aim IV.